Highly dispersed Ni–Fe active sites on a fullerene based electron buffer to boost the oxygen evolution reaction

Abstract

It is critical to develop highly efficient electrocatalysts for water splitting to achieve energy-saving hydrogen production. Recently, fullerene-based electrocatalysts have been widely reported for the cathodic hydrogen evolution reaction (HER), while their application for the intrinsically sluggish oxygen evolution reaction (OER) at the anode has been rarely explored. Herein, a novel OER electrocatalyst, NiFe-OC₆₀, was prepared by introducing Ni and Fe species onto fullerol C₆₀(OH)_x. The fullerene-based carbon support can provide a high surface area and serve as an electron buffer due to its inherent electron-withdrawing properties. Besides the synergistic effects between Ni and Fe, the fullerene-based carbon support promotes the generation of high-valence Ni³⁺ species, thus contributing to improved OER performance. The as-synthesized NiFe-OC₆₀ supported on the glassy carbon electrode exhibits excellent OER results with a relatively small overpotential of 314 mV at a current density of 10 mA cm⁻² and a small Tafel slope of 38.62 mV dec⁻¹ in alkaline solution. Our work demonstrates fullerene-based materials as promising electrocatalysts for emerging clean-energy related technologies.